摘要
石楼北区块位于鄂尔多斯盆地东缘。该区域表土层松散易坍塌,在以往的钻探施工中,地层中不同程度的存在涌水或者漏失情况。太原组第三层灰岩可钻性较差,取心作业中频繁发生钻头被堵死的情况。为了解决以上问题,缩短施工工期,对钻具组合和钻井参数进行了调整,采用四翼PDC钻头、直螺杆的钻具结构;取心作业主要采用绳索取心,采用Ф215.9mm的取心钻头代替该区以往的Ф16.9mm钻头,利用Ф127mm钻杆作为绳索取心工具的运行通道,并采用自行研制的内外管总成和内管取心工具,保证了取心效果;将钻头水眼更改为12mm×2+14mm+16mm的组合方式,有效保持了钻孔内的清洁,避免岩屑重复破碎,进一步提高钻进效率。同时介绍了钻探施工程中设备的配套、钻井液的配制、钻井技术参数的选择等。结果表明:该井取心岩心总收获率为92.15%,其中8#煤心质量总采取率为93.50%;井斜3°10′,全井水平位移44.17m,最大全角变化率≦1.1°/30m。对该区煤层气井钻探施工有很好的借鉴作用。
The Shilou north block is situated at the eastern margin of Ordos Basin. The overburden in the area is loose and easy to col- lapse; varying degrees of water gushing and circulation loss have been happened in past drilling operations. The No.3 limestone in Tai- yuan Formation has poor drillability, bit bailing happened frequently during coring. To solve above issues and shorten operation period, carried out regulations for drilling assembly and drilling parameters, thus using 4-wing PDC bit, frank screw drills, wire-line coring, 215.9mm coring bit replacing q^169mm coring bit, dP127mm rod as wire-line coring channel and self manufactured inner, outer tube assembly, inner tube coring tool have ensured coring effect. Bit nozzle has been modified into 12mmx2＋ 14mm＋ 16mm array mode, thus effectively kept borehole clean, avoid cuttings repeatedly crushing, raising drilling efficiency a step further. Meanwhile, the equipment combinations, drilling fluid formulation, parameter selection during drilling operations have been introduced. The result has shown that total core recovery of the well is 92.15%, in which, total core recovery of No.8 coal is 93.50%; well deviation 3~10＇, horizontal displace- ment 44.17m, maximum dip angle rate of change ~l.l~/30m. The study is a nice reference for CBM well drilling operations in the area henceforth.
出处
《中国煤炭地质》
2013年第12期72-74,82,共4页
Coal Geology of China
